Purifying pepsin by dialysis



UNITED STATES PATENT OFFICE.

JOHN B. RUSSELL, OF DETROIT, MICHIGAN.

PURIFYING PEPSIN BY DIALYSIS.

SPECIFICATION forming part of Letters Patent No. 414,591, dated November5, 1889.

Application filed April 24, 1889. Serial No. 808,431. (No specimens.)

To all whom it may concern-.-

Be it known that 1, JOHN B. RUSSELL, of Detroit, in the county of Wayneand State of Michigan, have invented a new and useful Improvement inManufacture of Pepsin, of which the following is a specification,

My invention consists in an improvement in the manufacture of pepsin,hereinafter fully described and claimed.

Pepsin is now usually obtained from the stomachs of hogs in two ways,viz: first, by scraping the mucus from the membranes of the stomach anddrying it, and, second, by macerating the mucous membranes or wholestomachs, sometimes after having been out or broken finely, inacidulated water, either cold or warm, (heat hastening the process,)

whereby the pepsin is principally liberated from the peptic glands byits solvent or digestive action. The solution resulting from macerationmay be treated in various ways. A portion of the ferment may beprecipitated by adding to the solution some substance such as commonsaltand then the precipitate is collected and dried; or the solution maybe clarified in other known ways and then evaporated to dryness. l

I My invention relates to this ,second mode of obtaining pepsin. In thismode, the pepsin being liberated by its solvent or digestive action onthe membrane or glands, (except the small portion which may be held onthe surface of the membrane) the resulting solution, when strained andfreed from fats and other undissolved matter, contains a mixture ofpepsin, peptone, and such soluble salts as are liberated during themaceration. Peptone or digested albuminous matter is in itself inert asa ferment, and Whenever a peptone is capable of digestive action onalbumen this is due to a mixture with the peptone of pepsin or someother digestive ferment. It follows that the digestive power of amixture of pepsin and peptone depends upon the percentage of pepsinpresent, and is weakened by any increase in the percentage of peptone,and this accounts for the low digestive power of a pepsin obtained bydissolving the whole membrane or stomach, clarifying or purifying thesolution, and then evaporating the solution to dryness.

animal membranes very slowly, while peptone and the soluble saltsliberated from the stomach during maceration pass through thesesubstances with comparative rapidity. I therefore place the solutionobtained by maceration and clarification, as above described, containingpepsin, peptone, and usually some soluble salts, in a dialyser of anyknown form of construction, using for manufacturing a dialyscr havinglarge surfaces of parchment paper or animal membrane, by which a largequantity of material can be worked at once.

During the process of dialysis I keep the solution somewhat acid, addinghydrochloric or other suitable acid in small quantities whenever thesolution approaches a neutral condition, and continue the process untilthe percentage of peptone is so reduced as to give a mixture of pepsinand peptone of the digestive power wished, (at present about onethousand to two thousand, in accordance with the United StatesPharmacopoeia test, Sixth Decennial Revision, 187 0,) when I remove thesolution from the dialyser and evaporate it to dryness.

What I claim as my invention, and desire to secure by Letters Patent,is-

.The herein-described process of manufacturing pepsin, consisting inmacerating hogs stomachs in acidulated water, either hot or cold,clarifying the resulting solution in any known way, subjecting theclarified solution to dialysis, whereby the percentage of peptonepresent is reduced, and finally evaporating the moisture from theremainder of the solution.

JOHN B. RUSSELL. WVitnesses:

GEO. H. LOTHEOP, ADELAIDE A. ANDERSON.

